The mockumentary form, which once seemed a refreshing innovation, has become a standard element in the sitcom toolkit (while disappearing from the movies, where it was born). Indeed, younger viewers may not remember a world without it. Counterintuitively, it’s formally conservative; whatever the subject, one mockumentary now looks quite a bit like another, with the side eyes and addresses to the camera and a sometimes desperate self-presentation on the part of its characters.

“The Office” did a lot of business for NBC, so here comes “St. Denis Medical,” also on NBC, which is “The Office” in a hospital — no one’s done that before. Justin Spitzer, co-creator with Eric Ledgin, created the workplace sitcoms “Superstore” (also NBC) and “American Auto” (also, also NBC) and wrote for “The Office” and “Scrubs,” a nonmockumentary hospital sitcom, so there is a certain Mendelian logic, not to say a practiced efficiency, to the whole thing.

As in many such shows — “Abbott Elementary,” characterized as the savior of network comedy, to name but one — the workplace at hand is something of an underdog.

St. Denis is a “small regional hospital” somewhere in Oregon, an underfunded “safety net” institution where everyone is treated and no one gets asked for their insurance. It’s populated, as hospital director Joyce (Wendi McLendon-Covey) tells the camera, with “some of the best doctors in the country, I mean in Oregon — carving out Portland, ’cause that’s a big city so they probably, well, you get it.” She nevertheless dreams of making it a “destination medical facility” and buys a $300,000 3-D mammogram machine in pursuit of the goal, hopeful of attracting “women from as far away as Idaho because we have the best breast test ... in the West.”

Set around the hospital’s emergency room, which keeps the narrative compact and busy and requires fewer sets, it comes with the customary variety pack of characters. Allison Tolman plays newly promoted supervising nurse Alex, at the center of things in terms of action and authority, and more or less the stand-in for the viewer. Ron (David Alan Grier), the caustic, prankish senior doctor, calls her “a workaholic control freak,” but it is only because she cares.

As the most experienced physician on the floor, Ron, divorced and living on takeout food (“I ordered so much Postmates last month they sent me a gift card”), takes a more relaxed approach to his work, though not to the candy bar he ritually consumes each day. At one point, this sets him against Bruce (Josh Lawson), a preening, square-jawed trauma surgeon, who keeps a samurai sword and an electric guitar in his office and plays the Beastie Boys in the operating room, and who has bought the last Reese’s NutRageous in the hospital.

“I’m the Diana Ross around this place and you, you’re just one of the Supremes,” he says to Ron.

“You’re Diana Ross? You’re not even Bob Ross.”

Also featured is Mekki Leeper, who wrote and starred in “Jury Duty,” as Matt, a novice RN who grew up in a Montana religious community “that doesn’t believe in ‘medicine’ ”; as the just-arriving character, he’s idealistic, because he’s naive, and will have much to learn. As nurse administrator Val, Kaliko Kauahi — who, like Lawson, was on “Superstore” — knows how things work and how to work them, while Kahyun Kim’s nurse Serena represents youthful, sparky, self-assured attitude. And there, as Peter Quince said to the rude mechanicals, “is a play fitted.”

The cast is impeccable. Tolman is reason enough to turn on the television, though I have not quite forgiven television for its shabby treatment of the last two series in which she starred, the science-fiction drama “Emergence” and the delicate thinking-animal comedy “Downward Dog.” Grier, the veteran player playing the veteran doctor, is contagious easiness itself. And selling herself and her hospital to the camera crew, McLendon-Covey turns herself up high, a tempest of real and forced enthusiasm.

It’s perfectly fine — consistently amusing, sometimes funny, basically sweet, a little sentimental in the finish. In terms of linear television, it’s more tent than tentpole, but the canvas is sound; there are no rips developing, no threadbare patches to let the rain in.

The only slightly negative thing I can say about it is that, though the characters are established fairly quickly, in the six episodes out for review they remain emotionally independent. There are no relationships for the viewer to focus on, which is what kept “The Office” on the air for nine seasons and makes it a valuable property more than a decade after it left the air.

That might come, of course — sitcoms, if they’re allowed to go on, tend to mature like wine — or it might not. One never knows. Until one knows.

How to watch: Tuesdays on NBC