Like Monet, de Kooning (1904–1997) lived one of art’s great careers: a long arc that stretched from early years as a revolutionary, to mid-years as an acclaimed master, and on to a long late period of relative critical neglect as the avant-garde chugged past. As was also the case with Monet, de Kooning’s late work has gained renewed interest after his death. Two museum-quality exhibitions focus on the last great flowering of de Kooning’s painting in the 1980s.

Circumstances changed greatly for the artist around 1980. Under the renewed care of his long-estranged wife, Elaine, de Kooning quit drinking and embarked on another of the distinct phases of his career. At L&M Arts, 20 large canvases from between 1981 and 1986 hang in intimate grandeur about the gallery’s two floors. The earliest show traces of the luscious, brushy textures of the 1970s pastoral paintings, but on the whole a far leaner and simpler lyricism prevails, with calmer surfaces and clean-cut areas of color. The romanticism of de Kooning’s attack remains, but its brashness has mellowed into something closer to meditative play.

Even so, every foray is new. “Untitled VI” (1981) moves principally through shifts of intense colors — relatively same-size patches of deep ultramarine blue, scrapeddown steel-blue, tangy scarlet, and orange-reds — while in “Untitled VIII” (1982) a calligraphy of bold, blue strokes dominates and corrals undulating zones of red and white.

Later paintings hang mostly on L&M’s second floor. In his exhibition catalogue essay, Joachim Pissarro describes how de Kooning, despite encroaching Alzheimer’slike symptoms, retained his alertness as he turned to the “ribbon” paintings of the mid-1980s, with their predominately blue and red lines curling on fields of white. Indeed, the scale of his attack is still there, though it is accompanied by a slackening of tension; at points his gestures sift peaceably through space, as if ideas of gestures rather than their rhythmic embodiment. If L&M’s installation highlights the merits of individual works, Gagosian’s showcases the evolution of de Kooning’s final phase. Two dozen works from private collections and museums, presented in collaboration with the Johanna Liesbeth de Kooning Trust, hang spaciously about the gallery’s vast West 21st Street space. A visitor standing in the middle of the roughly chronological installation can absorb in a sweeping glance the development of his painting over the ’80s — and also measure them against several early pieces from the ’40s and ’50s that are interspersed throughout the hanging. Comparatively small and dark, these five works tellingly display what the artist retained and discarded over the decades. Again, the works from around 1980 are notable for their variety of attack. Shrill transparent green strokes, vigorously applied with a taper’s knife, test the horizontal and vertical dimensions of “Untitled V” (1980). In an untitled work from 1982, a scrim of light lines loops delicately through yellow-white fields. Despite its earthy, dense compaction of strokes, an untitled work from around 1979 radiates the impression of light on water with tiers of streaming yellow-green, blue, and white.

Gagosian’s installation details the shifting of his attack to the “ribbon” paintings, and the re-introduction of color in the late ’80s as evenly curling shapes. Together these works suggest an artist coming to peace with his ambitions and with the world.

But are they the culmination of a life work? The essay by curator Klaus Kertess in the catalogue compares de Kooning’s late paintings with those of Matisse and Gorky, while the strategic inclusion of works from the 1940s and 1950s underscores the stylistic continuity of the artist’s work over the decades. Despite such stylistic affinities, however, the early, “classic ” de Koonings also highlight the later canvases’ limitations. Nothing on a wall of 1980s paintings quite rivals the coordinated anarchy of the small “Fire Island” (c. 1946) — a restless bundle of funneling, inflating, jackknifing forms — that hangs at the wall’s center. In little more than 2 square feet it sums up everything he learned from Gorky and Picasso. Similarly, “Orestes” (1947) has a tautness of line exceeding any of the far larger, later canvases adorning another wall. Just as the “purple prose” of his turgid ’60s and ’70s canvases doesn’t automatically convince us of interior dramas, the tranquility of his last works doesn’t always suggest the profoundest of meditations.

But the late work does contain surprises. Back at L&M, the painting “Untitled VII” (1985) near the gallery entrance is nothing less than extraordinary. That signature de Kooning mark — the curve probing tensely forward before whipping back on itself — reappears, softenedbutdistinct, amidst crisp sweeps of orange-red, blue, and yellow. The canvas has a sleekness one would never have expected in earlier decades, but its forms collide and part with agile force. It could have been produced by no other painter. In his ninth decade, the artist was still finding new ways to paint.

L&M Arts until November 7 (45 E. 78th St., between Madison and Park avenues, 212-861-0020);

Gagosian Gallery until October 27 (522 W. 21st St., between Tenth and Eleventh avenues, 212-741-1717).