Pediatric Therapy in Westchester County
Most families arrive here after somebody said wait and see. Developmental Steps, LLC is a pediatric therapy practice owned and managed by two physical therapists, Joe Kiefer and Hayley Apiscopa, and one occupational therapist, Lacey Straub, with two clinics in Westchester County: one in Port Chester and one in Mt Kisco. We work with infants, preschoolers, grade schoolers and adolescents, on developmental and physical challenges and on sport specific strength and training. The line we hold ourselves to is simple. We treat every child here as if they were our own.
What makes this place different?
Developmental Steps was built to advance a child's development, which is a narrower job than it sounds. Adult clinics that also see children are not the same thing. Children are not small adults: their skills are still being assembled, their motivation runs on play, and the person who has to carry the work between visits is a parent, not the patient. So the practice is organized around children and the families raising them, in Port Chester and in Mt Kisco, with a range of solutions broad enough that most families do not have to go anywhere else. Our staff offers compassion to you as well as to your child, because you are in the room too.
Pediatrics is the whole practice
This is a pediatric therapy center, not an adult clinic with a corner set aside for kids. Physical therapy, occupational therapy and the community programs are all built for children, which shows up in the equipment, the language the therapists use and how a session is paced when a three year old has had enough.
Newborn through adolescent
We see infants and toddlers, preschoolers, grade schoolers and adolescents. That range matters, because a child who starts with us for tummy time resistance at four months may come back at nine for coordination, and the file, the history and often the therapist are already here.
A place to go while you wait
Developmental Steps is a CPSE provider. We are not an Early Intervention provider and do not offer Early Intervention services. Some families come to us while they wait on an Early Intervention evaluation or approval, and others after being told their child did not qualify, because they would rather start now than lose the months. Families whose child already receives Early Intervention through another agency can also see us privately alongside it. Either way, we work with where your child is today.
Owned and run by two physical therapists and one occupational therapist.
Developmental Steps, LLC is owned and managed by Joseph R. Kiefer, PT, who founded it, Dr. Hayley A. Apiscopa, PT, DPT, and Lacey Straub, OTR/L. All three are licensed therapists, which means the people setting the standard for care here still know what it takes to hold the attention of a two year old for 45 minutes. The full team is 18 people: licensed pediatric physical and occupational therapists, physical therapist assistants, a certified occupational therapy assistant, and the office staff who handle your insurance questions and your scheduling in Port Chester and Mt Kisco. It is a small enough practice that your child gets to know the person treating them, which matters more than it sounds when a child is being asked to try something hard. Read every bio, credential and background on our team.
Three commitments behind every plan of care in Port Chester and Mt Kisco.
Developmental Steps hires experienced pediatric physical therapists and occupational therapists who are movement specialists, with the specialized skills and training that infants, toddlers and young children actually require. That bar is why students train here, and why some of them come back as staff. We also tell you which credential each person holds, because a family deserves to know who is in the room with their child.
Every child gets a thorough assessment before anyone writes a treatment plan, because a tilt, a delay or a pattern of falling can come from more than one place. From there it is 45 minutes of one on one work aimed at posture, strength and symmetry, the building blocks that carry a child forward for years, not just to the next milestone.
We run two clinics, one in Port Chester and one in Mt Kisco, and we also treat in several schools across central Westchester County. Our tummy time workshops are free and open to any parent who wants them, whether or not their baby ever becomes a patient here.
The same faces, visit after visit.
Eighteen people work here: physical therapists, physical therapist assistants, occupational therapists and the staff who answer the phone and sort out your insurance. They see children across two clinics, Port Chester and Mt Kisco, and in several schools around central Westchester County. Credentials differ by role, and every one of them is listed below, exactly as it is held.
Joseph R. Kiefer
Joe has practiced since 1994, with a Masters in Physical Therapy from Hahnemann University and an internship at the Georgetown University Child Development Center. He was a senior pediatric therapist at United Cerebral Palsy before founding this practice in Westchester, and he has published in the Pediatric Physical Therapy Journal on fetal alcohol syndrome and cerebral palsy. His focus is motor learning and motor development in children. In his own words: "Developmental Steps is that 'Fun' Place. I love helping kids find a way to 'Do' something through a strategy, practice, or making it plain old fun." He lives in Katonah with his wife, two kids and two dogs, and gets to Vermont to ski and Montauk when he can.
Dr. Hayley A. Apiscopa
Hayley earned her Masters in Physical Therapy in 2003 and her Doctorate of Physical Therapy in 2006, both at Boston University, and has been with Developmental Steps, LLC since 2008. A former competitive gymnast, she works extensively with torticollis, hypotonia, cerebral palsy, neurological injuries and developmental delay, and she is the therapist who teaches the clinic's community tummy time classes. She lives in Katonah with her husband and two children.
Lacey Straub
Lacey holds a Master of Science in Occupational Therapy from Mercy College, earned in 2011, and is a board certified occupational therapist. Her expertise runs across sensory processing, fine motor delays, visual processing, executive functioning, therapeutic listening, motor coordination delays and handwriting. She spends her spare time with her husband and three children, and takes part in local school events in Brewster.
Deirdre Nebel
Deirdre graduated from New York Medical College in 2002 with a Masters in Physical Therapy, and joined Developmental Steps in September 2022. She started in pediatrics at the Children's Evaluation and Rehabilitation Center in the Bronx, then worked at Kidabilities and Los Ninos Services in Hawthorne and at ACDS of Scarsdale and Easter Seals Project Explore in Valhalla, including preschool transition preparation. She lives in Valhalla with her husband and three daughters, and coaches their soccer teams.
Dr. Autumn Grey
Autumn earned her Doctorate of Physical Therapy from Ithaca College in August 2024, after a Bachelors in Clinical Health Studies, and joined Developmental Steps that December. During her doctoral training she provided therapeutic services in a school setting, so classroom and playground demands are familiar ground for her. She lives in Elmsford, and outside the clinic she cooks, plays tennis, goes to concerts and spends time with her dogs.
Dr. Casey Brooks
Casey earned her Doctorate of Physical Therapy from Northeastern University in 2013. She began in an outpatient orthopedic clinic in San Diego, then worked in home health and acute rehabilitation around Boston. Becoming a mother of two young toddlers and moving back to New York, where she grew up, turned her toward pediatrics, and she joined Developmental Steps, LLC in 2024. She walks her dogs, runs and cooks when she is not with family and friends.
Dr. Kelly Hoisl
Kelly earned her Doctorate in Physical Therapy from the University of Connecticut in 2021, after a Bachelor's in Kinesiology from the University of Rhode Island. She began her career in outpatient orthopedics and has since worked in a skilled nursing facility, a private special education program and an outpatient pediatric clinic. She joined Developmental Steps, LLC in spring 2025. She lives in Stamford, Connecticut, and likes baking, travel, the beach and finding new restaurants.
Dr. Gabriella Pagnotta
Gabriella earned her Doctorate of Physical Therapy from New York Medical College with the class of 2025. Her clinical training included an international rotation in Florence, Italy, and a rotation here at Developmental Steps, mentored by Hayley and the clinical team, after which she accepted a full time position on graduating. Born and raised in Westchester, she stays active, takes on DIY projects, travels and likes trying new food.
Dr. Leila Miller
Leila decided on pediatric physical therapy at eleven years old, after a personal experience with her younger brother. She has clinical experience in outpatient pediatric and school based settings, working with autism spectrum disorder, developmental delay, cerebral palsy, Down syndrome, hypotonia, achondroplasia and other neurological and genetic conditions. She lives in Elmsford, reads, exercises, and is a self described big Marvel Cinematic Universe fan.
Dr. Marisa Mariani
Marisa earned her Doctorate in Physical Therapy from Sacred Heart University in 2024, after completing her Bachelor's in Exercise Science there in 2020. Her final clinical rotation, at Le Bonheur Children's Hospital Outpatient in Memphis, put her with medically complex children and is what sparked her passion for pediatric physical therapy. She began in an outpatient orthopedic and sports medicine setting, then worked in a private outpatient pediatric clinic with children receiving Early Intervention and CPSE services. She believes therapy should be engaging, encouraging and fun. She lives in White Plains, and practices yoga, bakes, sees Broadway shows and takes long walks with her dog.
Diana Gomez Schneider
Diana earned her associate's degree as a physical therapist assistant and massage therapist in 2001, and brought more than five years of experience as a PTA across pediatrics, athletics, post surgical rehabilitation and geriatrics when she joined Developmental Steps, LLC in spring 2020. She has also worked as a massage therapist, a personal trainer and a fitness instructor. She treats in schools, at camps, in backyard training sessions and in the office. She lives in Katonah with her husband and three children, all of them in multiple sports.
Tara Murphy
Tara joined Developmental Steps in July 2019, after earning her degree at Norwalk Community College. She lives in White Plains, takes kickboxing and yoga classes, runs, hikes and plays soccer, and spends her free time with family and friends, including teaching her young cousins to play sports.
Brenna Wassil
Brenna earned her Master of Science in Occupational Therapy from Mercy University in 2025. She taught preschool for eight years while she worked toward that degree, and she has experience in school based settings with children of all ages, which is a useful combination when the goal is a skill a child needs in a classroom. A lifelong Westchester resident, she crafts and cooks outside the clinic.
Sierra Taplin
Sierra is an occupational therapist with a Master's degree from Quinnipiac University's Accelerated Occupational Therapy Program. Sierra has worked with children of varying abilities in school based settings, from elementary through high school, including children with autism, cerebral palsy and coordination disorders, and builds sessions around visual motor and visual perceptual skills, fine motor development, motor planning, sensory regulation and body awareness. Earlier work as a community habilitation worker, personal care aide and K-8 aftercare worker shaped a passion for helping people take part in daily life. Originally from Putnam County, NY, Sierra enjoys time with family and friends, thrifting and the gym.
Danielle Gentile
Danielle holds a Master of Science in Occupational Therapy and has worked with children across a range of pediatric settings, supporting developmental, sensory, motor and functional needs. Clinical experience also includes upper extremity rehabilitation at Hospital for Special Surgery. Sessions are play based and purposeful, building sensory regulation, fine and visual motor skills, motor planning, coordination, attention and independence in everyday activities. A Westchester native, Danielle enjoys cooking, hiking, Pilates and the outdoors, and volunteers with the Miracle League of Westchester.
Melissa Infantino
Melissa earned her associate's degree in occupational therapy in 1999 and has spent her entire career in pediatrics. Before joining us, that career ran through Early Intervention, CPSE home care and school based settings, and for the past nine years she has supported K-12 school district programs. She lives in Hawthorne with her husband and two children, and says her favorite hobby is watching her children play various sports and volunteering at school events.
Sofia Dinunzio
Sofia is our part time office manager, and she handles medical claims, insurance reimbursement and benefit verifications. In practice that means she is often the person who helps a family work out what their plan actually covers before the first visit. She is also a stay at home mom to two children, and spends her time reading, cooking and teaching her kids Italian, with the beach in summer and apple picking in the fall.
