[3] On March 26, all nonessential businesses were closed and Governor Chris Sununu advised people to only leave home for essential necessities.

On March 29, the New Hampshire Department of Health and Human Services (DHHS) launched a dashboard with daily updates regarding the spread of the coronavirus in the state.

[22] The man with the first case had defied quarantine orders and attended a private event organized by Dartmouth College's Tuck School of Business in White River Junction, Vermont, on February 28.

[29] In April, COVID-19 outbreaks were reported in long-term care facilities and nursing homes in Greenfield,[30] Manchester,[31][32] Nashua,[33][34] Concord, Salem, Dover,[35] Derry[36][37] and Franklin.

[32] On August 2, the Foxwoods Resort Casino 301 NASCAR race was held at New Hampshire Motor Speedway with 12,000 to 15,000 fans in attendance, "the largest gathering for a sports event in New England since the onset of the coronavirus pandemic.

[48] On March 26, Sununu announced a stay-at-home order going into effect the following day at midnight requiring the closure of all non-essential in-person businesses.

These orders increased funding (21,[51] 22 [52]), modified governmental procedure to follow health guidelines (23,[53] 29,[54] 35,[55] 37,[56] 38 [56]), extended the state of emergency in New Hampshire (2020-05,[57] 2020-08 [55]), clarified or amended previous orders (24,[58] 25,[59] 2020-07 [60]), restricted hotels to vulnerable populations and essential workers (27 [61]), created plans to isolate COVID-19 positive first responders and homeless folks (28 [54]), outlined new healthcare or health insurance requirements (30,[54] 34,[55] 36 [55]), established the Governor's Office for Emergency Relief and Recovery (2020-06 [62]), established the COVID-19 Long Term Care Stabilization Program (31 [63]), extended previous orders implementing remote instruction for public k-12 schools (32 [64]), activated the New Hampshire Crisis Standards of Care Plan (33 [65]).

[67][68] Residents with COVID-19 symptoms, underlying health conditions, age over 60, or are healthcare workers can use the portal to request testing without medical referral.

[74] This included eliminating the 10-people-or-under limit for group gatherings and allowing businesses previously deemed non-essential (such as gyms, libraries, and pools) to re-open or expand.

[75] On June 25, New Hampshire Motor Speedway announced that it would welcome fans for a NASCAR race on August 2 following guidelines from Sununu to restrict attendance to 35% capacity; the event had originally been scheduled for July 19.

On August 11, Sununu issued an executive order mandating masks for all social gatherings of over 100 people, in anticipation of Laconia Motorcycle Week.

[78][79] On November 20, a statewide mask mandate went into effect, per an executive order from Sununu, applicable to "anyone over the age of 5 in indoor public spaces and outdoors when social distancing cannot be maintained.

[81] On April 15, 2021, Governor Sununu lifted the mask mandate, given that vaccinations were increasing, deaths were decreasing, and hospitalizations "remain manageable.